1. Technical Field
This invention relates to a room temperature-curable organopolysiloxane composition, and, more particularly, relates to a room temperature-curable organopolysiloxane composition which does not suffer from fissuring or cracking when its adherend (substrate) undergoes movement during the course of its cure.
2. Prior Art and Problems to Be Solved by the Invention
Room temperature-curable organopolysiloxane compositions have a number of excellent properties, and as a result are employed as sealants and adhesives in various fields, for example, in civil engineering and construction, in general industry for machinery and tools, and in the electrical and electronics sectors. A problem associated with this type of composition is the development of surface fissuring when the composition is subjected to external stress (e.g., tensile stress, flexural stress) during the course of its cure.
As a result, the substrate or device carrying the room temperature-curable organopolysiloxane composition cannot be moved until the composition has undergone some degree of curing and surface skin strength has developed. This requires a long, disturbance-free holding period.
The present inventors carried out extensive investigations directed at solving this problem, and as a result they discovered that this problem can be solved in a single stroke by the addition of a specific type of hydrophobic silica to room temperature-curable organopolysiloxane compositions. The present invention was developed based on this finding.